Question: Express this product in scientific notation: $(9.90\times 10^{-4})\times (8.00\times 10^{-3})$
Explanation: Start by collecting like terms together. $= (9.90\times 8.00) \times (10^{-4}\times 10^{-3})$ When multiplying exponents with the same base, add the powers together. $= 79.2 \times 10^{-4\,+\,-3}$ $= 79.2 \times 10^{-7}$ To write the answer correctly in scientific notation, the first number needs to be between $1$ and $10$ . In this case, we need to move the decimal one position to the left without changing the value of our answer. $ $ We can use the fact that $79.2$ is the same as $7.920 \times 10$ $ = {7.920 \times 10} \times 10^{-7} $ $= 7.920\times 10^{-6}$